|Publication number||US4559480 A|
|Application number||US 06/551,800|
|Publication date||17 Dec 1985|
|Filing date||15 Nov 1983|
|Priority date||15 Nov 1982|
|Also published as||CA1212711A, CA1212711A1, DE3376366D1, EP0109671A1, EP0109671B1|
|Publication number||06551800, 551800, US 4559480 A, US 4559480A, US-A-4559480, US4559480 A, US4559480A|
|Original Assignee||Omega Sa|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (12), Referenced by (129), Classifications (11), Legal Events (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention concerns a light emitting element intended for use in a matrix display board.
Up to the present time two types of elements have been proposed and employed for use in display boards: incandescent lamps and cathode ray tubes.
The main difficulties of incandescent lamps reside in their high power consumption (between 20 and 40 watts per element) and their relatively low yield (about 10 lumens per watt). It will also be noted that such lamps are relatively short-lived (average 1000 hours) and have a colour temperature which is variable as a function of the energizing voltage at the terminals thereof as well as a progressive diminution of the luminescent intensity because of the interior blackening of the bulb as a function of the length of service. Such elements have likewise been proposed to equip display boards in colour. In such cases for each pixel three lamps are required associated with coloured filters, or more simply, three lamps each having a coloured bulb. It will be however understood that for colour the difficulties mentioned above in respect of black and white displays are entirely present. On the positive side however it may be said that incandescent lamps are inexpensive elements easily changed and readily to be found on the market.
Thus, in a practical example, a black and white screen of 4.3 m high and 8.6 m wide comprises 160 lines and 80 columns, thus requiring 12,800 incandescent lamps. If the rating of each lamp is 25 W, the power necessary to energize all of them simultaneously to full luminosity will be on the order of 320 kW. It will be readily understood that such as screen requires a high capacity power source as well as a very considerable energy expense.
Cathode ray tubes have been used in colour screens as may be seen in the British patent publication No. 2 053 547 and U.S. Pat. No. 4,326,150. Although these concern a tube of which the manufacture is simplified relative to those known in television tubes, it is nonetheless quite complex and above all necessary to employ very high acceleration voltages therewith, this complicating considerably the realization of the assembly. Such a tube has however the advantage of a low energy consumption compared to that of an incandescent lamp.
To overcome the difficulties mentioned above, the present invention proposes a light emitting element comprising at least one discharge tube containing mercury vapour at low pressure the internal wall of said tube being coated with a fluorescent substance.
Such an element is known of itself but seems not to have been previously proposed for use in a matrix display board. In most cases it is applied in domestic lighting or for luminous signs.
In the first case, variable length tubes which may be straight or curved, have at each end electrodes which may be constituted by a filament coated with an emitting layer of oxyde. The gaseous atmosphere within the tube is comprised of argon for start-up at a pressure of several millimeters of mercury and of a drop of mercury. The discharge in the mercury vapour effects essentially ultra-violet radiation at a wavelength of 253.7 nm. The wall of the tube appears white from the nature of the fluorescent substance (phosphor) applied on the interior wall and intended to convert the ultra-violet radiation into visible light.
Certain luminous signs use a type of tube known as luminescent for which the discharge in the gas creates directly the luminous effect. In this case, the wall of the tube is either transparent or coloured without employing however the fluorescent phenomenon. The arrangement described in British specification No. 354 908 makes use of tubes filled with neon which gives an orange-red colour or mercury vapour which gives a blue colour. However the arrangement shown does not in any way constitute a matrix display since it comprises a multitude of rectilinear segments of various lengths and interlaced in such a manner as to form a letter or number by the illumination of a predetermined number of the segments. The light emitting element described in the German specification No. 2 031 610 also makes use of neon tubes to set up a display system for moving script. The cited element comprises three tubes emitting different colours. However no means are shown for mixing the colours so as to permit the obtaining at the element output light the resultant wavelength of which may vary throughout the visible spectrum. Generally luminescent tubes are poorly adapted to use in a matrix display since in order to obtain the three fundamental colours one is obliged to combine the filling gas with the colour of the tube, this leading to elements which will not emit the same light intensity for each of the three tubes.
With respect to the incandescent lamp, the fluorescent tube presents several advantages. It has a high yield of light on the order of 40 lumens per watt, this resulting for a comparable luminous flux in a considerably diminished energy consumption. The average life span exceeds 7,500 hours, this contributing to increase the reliability of the entire display. It likewise displays a very greatly diminished heat output this having as effect to reduce convection currents and blackened trails of dust brought about by such convection. Finally the tube displays a colour temperature which is invariable as a function of the luminosity by as well as a very feeble blackening of the bulb, localised at the placing of the electrodes, as a function of its length of service.
Relative to the cathode ray tube, the fluorescent tube shows energy consumption approximately the same. On the other hand, its price is considerably lower and it does not require to be energized at a high voltage. Finally, the number of electrodes is reduced.
Thus, the use of a fluorescent tube in a giant display screen as foreseen in the present invention enables the offering of a new and advantageous product by virtue of its lower energy consumption, the quality of the images presented and its reasonable price.
FIG. 1 is a schematic representation of a display board in accordance with the prior art.
FIG. 2 shows an element adapted to emit white light and using a single fluorescent tube in accordance with a first variant of the invention.
FIG. 3 shows a coloured light emitting element equipped with three fluorescent tubes in accordance with a second variant of the invention.
FIG. 4 shows the element of FIG. 3 seen from its face in accordance with a first arrangement of the tubes.
FIGS. 5 and 6 show light emitting elements according to other possible arrangements of the tubes than that shown in FIG. 4.
FIG. 7 is an electrical schematic showing the energization principle of a light emitting element employing three coloured fluorescent tubes.
FIG. 8 is a timing diagram showing the feed voltage and the respective currents circulating in each of the light emitting elements.
FIG. 1 shows a matrix board as known from the prior art. The board 1 as shown is equipped with incandescent lamps 2 arranged in rows and in columns adjacent one another. Such an arrangement presently used in sports stadiums may be realized in large dimensions. Coupled to the display board by cable 3 one may find a control center 4. Such center is equipped with all the apparatus necessary for the transmission of static or moving images. It is thus possible to display texts such as sporting results, advertising matters, animated events or playbacks of such events by means of cameras, disks, magnetic tapes, etc. For each pixel there corresponds an incandescent bulb should the display be in black and white. An arrangement may then permit varying the luminous intensity produced by the bulb in order to arrive at multiple shades of light which may compose an image. In the case of displays in colour, each of the pixels may comprise three incandescent bulbs (red, green, blue) or three cathode ray tubes. By separately varying the luminous intensity produced by the three elements, one may arrive at a resulting light the wavelength of which may cover the entire visible spectrum.
As has already been set forth in the introduction, the present invention aims to replace the incandescent lamps or cathode ray tubes by at least one discharge tube generally known as a fluorescent tube in order to form the light emitting element or pixel. FIG. 2 shows such an element 24. The fluorescent tube 5 is mounted in a compartment 6. In order to respond to the physical laws which govern and in recalling that the power of the light emitted is a function of the length of the tube, tube 5 must have a certain length. In order to arrive thereat, it is preferable for the present purpose to give it a U form. Thus the visible face 7 of the element remains within dimensions which are compatible with the matrix display proposed, that is to say about 80 cm2, this representing a square of about 9 cm on each side.
It will be understood however that in order to utilize the entire luminous radiation of the tube, thus as well that of the rectilinear portions, it will be necessary to provide a reflecting system returning the light coming from said rectilinear portions towards the front part of the element. This may be obtained for example by means of a reflector placed behind the compartment at wall 8, this reflector being completed according to the geometry of this compartment by a diffusing mirror forming the walls 9 of the compartment.
The compartment shown in FIG. 2 is a parallelepipedon. One may readily imagine other geometries without departing from the present invention. Thus the compartment could be triangular with the summit of the triangle where the tube electrically is connected, this with the purpose of improving the reflection effect presented by the walls. Moreover, the front face could be provided with an anti-reflection system.
The light emitting element which has just been described may be employed in black and white display boards. The element will be provided with a socket for electrical connexions and a simple system of attachment in order to render it easily detachable. Thus conceived it will be readily interchangeable and very accessible to maintenance personnel.
FIG. 3 shows a pixel 24 for coloured light provided with three fluorescent tubes. It is distinguished from what has been shown in FIG. 2 only by the juxtaposition of three fluorescent tubes of different colours 10, 11 and 12. As has already been said above, it is the fluorescent substance applied onto the wall of the tube which transforms the ultra-violet radiation of the discharge into visible light. Thus, in the pixel of FIG. 3 tube 10 radiates in the red (one might use for instance calcium borate as a fluorescent substance), tube 11 in the green (willemite) and tube 12 in the blue (calcium tungstate). With a mixture having suitable proportions of the several substances, one may produce white light and it is such a mixture which may be utilized for the tube shown in FIG. 2.
It may be mentioned that the three base colours may also be obtained by means of three white light emitting tubes each completed by a coloured filter independently located in front of the tube. If this arrangement presents the disadvantage of adding extra components and diminishing the light yield it has however the advantage of requiring only tubes of a single white colour and which will necessitate no particular preparation as to the fluorescent substance.
Should one independently vary the intensity of the light emitted by each of the three coloured tubes one obtains light at the output of the element the resultant wavelength of which may vary from violet to red, that is to say from 330 to 700 nm it being understood that the observer remains a certain distance from the front face of the element.
The same observations which have been made vis-a-vis the white-black element may be made for the coloured element (reflectors, forms of the compartment, anti-reflection system, detachable construction). For certain special arrangements care should be taken to separate the colour tubes by bulkheads 13.
FIG. 4 is a face view of the element 24 of FIG. 3. From this view one may foresee various dispositions of the tubes in the light emitting element where, for instance,
FIG. 5 shows a disposition where the tubes are arranged end to end in order to circumscribe a closed surface, here a triangle, and
FIG. 6 shows an arrangement in spiral where the tubes seen from the front face present portions of circles. The ends of these portions are bent at 90° to form rectilinear portions which extend behind the plane of the figure.
Other dispositions than those shown in FIGS. 4, 5 and 6 may be envisaged without departing from the object of the invention. Thus the coloured element is not limited to utilization of three tubes. A fourth tube for instance could be added which in certain circumstances may improve the continuity of the luminous spectrum.
For the application herein proposed, one will utilize preferably hot cathode fluorescent tubes where at each end of the tube is to be found an electrode formed by a filament. The feed voltage is applied to each of the electrodes in order to provoke the discharge in and lighting up of the tube. When such a tube is used for domestic lighting at standard line frequency, it is generally necessary to provide a starter and a ballast inductance in order to limit the current. It is known that such an arrangement causes a certain delay in the lighting up which naturally is unacceptable for the present application where one wishes to display not only static texts but also moving images coming from living scenes (camera or television pick-up). Energization at high frequency permits not only an instantaneous lighting up of the tube but further a diminution of the energy consumed on the order of 20% since the luminous yield of the tube increases with the frequency. This arrangement permits also reduction of the ballast volume, and consequently the weight and the price. Such energization is briefly described in "Hexfet Databook, International Rectifier, 1981" at the paragraph "fluorescent lighting".
FIG. 7 shows a possible schematic for energizing an element 24 according to the invention. Here the element comprises three fluorescent tubes 20 (red), 21 (blue) and 22 (green). A power generator 23, dimensioned to feed a plurality of elements, provides a voltage Ug the frequency of which is chosen to be between 5 to 30 kHz from the line voltage Us. Filaments 25 to 30 are fed by means of the common transformer 31 connected to filaments 26, 28 and 30 and transformers 32, 33 and 34 to feed respectively filaments 25, 27 and 29. The primary winding of each of these transformers is connected to the energy source Ug.
It is to be noted that transformer 31 may likewise be dimensioned to feed a plurality of pixels and not only the three tubes forming a single light emitting element. To insulate galvanically filaments 25, 27 and 29 from the corresponding filaments 26, 28 and 30, it is necessary to provide three separated transformers 32, 33 and 34 or a single transformer having several secondary windings. It will be noted that these transformers are of reduced dimensions since they function at a high frequency.
The tubes 20, 21 and 22 are fired by acting respectively on the elements 35, 36 and 37 placed in series in the circuit of the tube and which are shown on the figure in the form of switches. The circuit of each of these tubes is respectively completed by an element 38, 39 and 40 which has for its purpose to stabilise the current flowing in the tube. This element may be a resistance, an inductance or a capacitor. The first case is of little interest since the resistance may bring about additional losses. In the two other cases, the elements may be of small dimensions in view of the high frequency.
According to the invention, the light intensity furnished by each of the tubes will depend in this system on the time during which the respective switch remains closed relative to a predetermined reference period. Thus, if judicious choice is made of the elementary colours for each tube and if the luminous flux emitted by each one is regulated by the duration of the closing of its respective switch, there will be obtained a colour which will be the result of a mixture of each of the luminous fluxes and which may extend over the entire visible spectrum.
Switches 35, 36 and 37 may take various forms, for example in the form of triacs controlled by video signals generated by a video camera via an analog-digital converter with appropriate control logic. Here will be found means known from the state of the art and which are applied to colour matrix display boards already found on the market.
FIG. 8 is a timing diagram showing the feed voltage Ug applied to the terminals of the tubes and the currents I20, I21 and I22 circulating in each of them as a function of the closing respectively of the control elements 35, 36 and 37. In this diagram, the first line represents the feed voltage Ug furnished by generator 23 (see FIG. 7). The voltage is provided by the juxtaposition of reference periods Tr comprising each at least 64 cycles Ta. The tube 20 (red) is energized at the luminous intensity desired by closing element 35 during a period T1 ≦Tr from whence there results a current I20 in the tube. In the same manner one proceeds for tubes 21 (blue) and 22 (green) during periods T2 and T3 respectively from whence there results currents I21 and I22. As has been explained above, the resulting colour at the output of the element will depend on the relative turn-on time of each of the tubes during the reference period. In other terms, one may say that the luminous intensity emitted by a single tube will be controlled by inhibiting a variable number of cycles Ta during the period of reference Tr. This is likewise true for a tube radiating a white colour, whence this type of energization may also be applied to a black and white board.
Matrix boards of the black-white type already known employ 16 shades of grey between black and white, thus permitting a suitable reproduction of video images. In such case, a digitalized signal of 4 bits is sufficient. However, it will be noted that for a colour display, on the one hand, it is desired to have a variation of luminous intensity relative to a predetermined colour--as for black and white--and, on the other hand, it is desirable to separately vary the luminous intensity of each of the three tubes in order to create the determined colour. Consequently a control based on 4 bits signal is not sufficient. Practical experience has shown that it is necessary to provide at least 64 different shadings which requires that the reference period Tr as mentioned above relative to FIG. 8 must comprise at least 64 cycles, this necessitating a digitalized signal of 6 bits. Still better results are obtained with 128 cycles (7 bits) or 256 cycles (8 bits), this permitting to adapt to the visual perception according to a logarithmic function for instance.
The energization of the light emitting element is not limited to the description hereinabove. In a variant which has not been shown on the drawing, instead of varying the number of cycles during the reference period one may vary the width of these cycles. One is thus led to a modulation by the pulse width (PWM).
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2015885 *||17 Apr 1933||1 Oct 1935||Meaf Mach En Apparaten Fab Nv||Method of producing a source of light|
|US4071809 *||13 Nov 1975||31 Jan 1978||Weiss J M||Apparatus for synthesizing of colors|
|US4208618 *||20 Sep 1978||17 Jun 1980||Westinghouse Electric Corp.||Compact single-ended fluorescent lamp|
|US4283659 *||7 Apr 1980||11 Aug 1981||The Singer Company||Display system utilizing incandescent lamp multiplexing|
|US4326150 *||20 Mar 1980||20 Apr 1982||Mitsubishi Denki Kabushiki Kaisha||Cathode ray tube device for display system|
|US4347460 *||3 Mar 1980||31 Aug 1982||Gte Products Corporation||Compact fluorescent lamp assembly|
|US4368485 *||13 Apr 1981||11 Jan 1983||Zenith Radio Corporation||Billboard large screen TV|
|US4486749 *||3 Jun 1982||4 Dec 1984||Futaba Denshi Kogyo Kabushiki Kaisha||Fluorescent display device|
|DE2031610A1 *||26 Jun 1970||24 Feb 1972||Pgh Neontechnik U Anlagebau Le||Title not available|
|GB354908A *||Title not available|
|GB2053547A *||Title not available|
|JPS54160070A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4715687 *||23 Dec 1986||29 Dec 1987||International Business Machines Corporation||Color variation in a passively illuminated display using fluorescent light sources|
|US4748546 *||2 Feb 1987||31 May 1988||Allied-Signal Inc.||Fluorescent backlighting unit|
|US4786841 *||22 Jun 1987||22 Nov 1988||Gte Products Corporation||Low-pressure arc discharge lamp having increased surface brightness|
|US4857900 *||12 Dec 1985||15 Aug 1989||Canon Kabushiki Kaisha||Display device with color correction|
|US4894645 *||27 May 1988||16 Jan 1990||Prisma Skyltreklam Ab||Incandescent matrix display with high frequency lamp driving|
|US4902939 *||25 Mar 1988||20 Feb 1990||Mosaic Rentals Pty., Ltd.||Display circuit|
|US4934768 *||27 Jun 1988||19 Jun 1990||Gte Products Corporation||Picture element lamp assembly for information display system|
|US4937487 *||16 Aug 1988||26 Jun 1990||Gte Products Corporation||Picture element lamp assembly for information display system|
|US4990821 *||27 Jun 1988||5 Feb 1991||Gte Products Corporation||Multicolor picture element with merged colors|
|US5003220 *||22 Jun 1987||26 Mar 1991||Gte Products Corporation||Integral lamp for tri-color picture element|
|US5003233 *||3 Jan 1989||26 Mar 1991||Gte Laboratories Incorporated||Radio frequency powered large scale display|
|US5005968 *||29 Aug 1989||9 Apr 1991||Asahi Kogaku Kogyo Kabushiki Kaisha||Contrast decreasing apparatus in image forming optical system|
|US5019750 *||16 Jan 1990||28 May 1991||Gte Products Corporation||Radio-frequency driven display|
|US5027041 *||16 Jan 1990||25 Jun 1991||Gte Products Corporation||Integrated radio-frequency light source for large scale display|
|US5963185 *||27 Sep 1996||5 Oct 1999||Texas Digital Systems, Inc.||Display device with variable color background area|
|US6018237 *||12 Aug 1997||25 Jan 2000||Texas Digital Systems, Inc.||Variable color display system|
|US6119073 *||17 Jun 1999||12 Sep 2000||Texas Digital Systems, Inc.||Variable color digital measuring instrument for sequentially exhibiting measured values|
|US6121767 *||24 Mar 1999||19 Sep 2000||Havel; Karel||Digital multimeter with variable color range indication|
|US6121944 *||8 Jun 1998||19 Sep 2000||Texas Digital Systems, Inc.||Method of indicating and evaluating measured value|
|US6133722 *||16 Jun 1999||17 Oct 2000||Texas Digital Systems, Inc.||Variable color digital measuring and testing system with error memory|
|US6147483 *||18 Jun 1999||14 Nov 2000||Texas Digital Systems, Inc.||Variable color digital voltmeter with analog comparator|
|US6157117 *||8 Jun 1998||5 Dec 2000||Taylor; Douglas||Tube lamp|
|US6166710 *||18 Jun 1999||26 Dec 2000||Texas Digital Systems, Inc.||Variable color display system for sequentially exhibiting digital values|
|US6181126||17 Jun 1999||30 Jan 2001||Texas Digital Systems, Inc.||Dual variable color measuring system|
|US6208322||23 Apr 1998||27 Mar 2001||Texas Digital Systems, Inc.||Color control signal converter|
|US6219014||18 Aug 1998||17 Apr 2001||Texas Digital Systems, Inc.||Variable color display device having display area and background area|
|US6239776||5 May 1998||29 May 2001||Texas Digital Systems, Inc.||Multicolor multi-element display system|
|US6281864||15 Mar 1999||28 Aug 2001||Texas Digital Systems, Inc.||Digital display system for variable color decimal point indication|
|US6300923||6 Jul 1998||9 Oct 2001||Texas Digital Systems, Inc.||Continuously variable color optical device|
|US6310590||11 Aug 1999||30 Oct 2001||Texas Digital Systems, Inc.||Method for continuously controlling color of display device|
|US6414662||12 Oct 1999||2 Jul 2002||Texas Digital Systems, Inc.||Variable color complementary display device using anti-parallel light emitting diodes|
|US6424327||11 Aug 1999||23 Jul 2002||Texas Digital Systems, Inc.||Multicolor display element with enable input|
|US6424998||18 May 1999||23 Jul 2002||World Theatre, Inc.||System permitting the display of video or still image content on selected displays of an electronic display network according to customer dictates|
|US6430603||28 Apr 1999||6 Aug 2002||World Theatre, Inc.||System for direct placement of commercial advertising, public service announcements and other content on electronic billboard displays|
|US6535186||16 Mar 1998||18 Mar 2003||Texas Digital Systems, Inc.||Multicolor display element|
|US6577287||20 Feb 2001||10 Jun 2003||Texas Digital Systems, Inc.||Dual variable color display device|
|US6647417||10 Feb 2000||11 Nov 2003||World Theatre, Inc.||Music distribution systems|
|US6690343||20 Mar 2001||10 Feb 2004||Texas Digital Systems, Inc.||Display device with variable color background for evaluating displayed value|
|US6734837||16 Jun 1999||11 May 2004||Texas Digital Systems, Inc.||Variable color display system for comparing exhibited value with limit|
|US6774583 *||8 Sep 2000||10 Aug 2004||Hongwei Zeng||Numerical controlled colour light source system|
|US6850901||24 Aug 2000||1 Feb 2005||World Theatre, Inc.||System and method permitting customers to order products from multiple participating merchants|
|US6952685||20 Jan 2000||4 Oct 2005||Ochoa Optics Llc||Music distribution system and associated antipiracy protection|
|US6965205||17 Sep 2002||15 Nov 2005||Color Kinetics Incorporated||Light emitting diode based products|
|US7015875||19 Jun 2002||21 Mar 2006||Novus Partners Llc||Dynamic device for billboard advertising|
|US7054256||19 Oct 2001||30 May 2006||Ochoa Optics Llc||High capacity digital data storage by transmission of radiant energy through arrays of small diameter holes|
|US7088352||11 Apr 2003||8 Aug 2006||Novus Partners Llc||Dynamic device and method for dispensing machines|
|US7098869||19 Jun 2002||29 Aug 2006||Novus Partners Llc||Business method for billboard advertising|
|US7098870||19 Jun 2002||29 Aug 2006||Novus Partners Llc||Advertising method for dynamic billboards|
|US7180252||18 Mar 2004||20 Feb 2007||Color Kinetics Incorporated||Geometric panel lighting apparatus and methods|
|US7209900||15 May 2001||24 Apr 2007||Charles Eric Hunter||Music distribution systems|
|US7233781||21 Nov 2001||19 Jun 2007||Ochoa Optics Llc||System and method for emergency notification content delivery|
|US7253566||10 May 2004||7 Aug 2007||Color Kinetics Incorporated||Methods and apparatus for controlling devices in a networked lighting system|
|US7303300||5 Sep 2003||4 Dec 2007||Color Kinetics Incorporated||Methods and systems for illuminating household products|
|US7358929||21 Apr 2004||15 Apr 2008||Philips Solid-State Lighting Solutions, Inc.||Tile lighting methods and systems|
|US7370016||6 Oct 2000||6 May 2008||Ochoa Optics Llc||Music distribution systems|
|US7377652||31 Jul 2007||27 May 2008||Dolby Laboratories Licensing Corporation||HDR displays having location specific modulation|
|US7403332||13 Mar 2003||22 Jul 2008||Dolby Laboratories Licensing Corporation||High dynamic range display devices|
|US7413307||5 Feb 2007||19 Aug 2008||Dolby Laboratories Licensing Corporation||High dynamic range display devices|
|US7413309||13 Feb 2008||19 Aug 2008||Dolby Laboratories Licensing Corporation||High dynamic range display devices|
|US7419267||31 Jul 2007||2 Sep 2008||Dolby Laboratories Licensing Corporation||HDR displays with overlapping dual modulation|
|US7543956||28 Feb 2006||9 Jun 2009||Philips Solid-State Lighting Solutions, Inc.||Configurations and methods for embedding electronics or light emitters in manufactured materials|
|US7581837||31 Jul 2007||1 Sep 2009||Dolby Laboratories Licensing Corporation||HDR displays and control systems therefor|
|US7598681||12 Jun 2007||6 Oct 2009||Philips Solid-State Lighting Solutions, Inc.||Methods and apparatus for controlling devices in a networked lighting system|
|US7598684||12 Jun 2007||6 Oct 2009||Philips Solid-State Lighting Solutions, Inc.||Methods and apparatus for controlling devices in a networked lighting system|
|US7599107 *||26 Feb 2007||6 Oct 2009||Seiko Epson Corporation||Electro-optical device, electronic apparatus, and driving method|
|US7623436||8 Mar 2006||24 Nov 2009||Charles Eric Hunter||High capacity digital data storage by transmission of radiant energy through arrays of small diameter holes|
|US7647618||28 Sep 2000||12 Jan 2010||Charles Eric Hunter||Video distribution system|
|US7649827||8 Mar 2006||19 Jan 2010||Charles Eric Hunter||High capacity digital data storage by transmission of radiant energy through arrays of small diameter holes|
|US7652436||3 Dec 2007||26 Jan 2010||Philips Solid-State Lighting Solutions, Inc.||Methods and systems for illuminating household products|
|US7692842||3 Apr 2009||6 Apr 2010||Seiko Epson Corporation||Electro-optical device, electronic apparatus, and driving method|
|US7753530||27 Jul 2009||13 Jul 2010||Dolby Laboratories Licensing Corporation||HDR displays and control systems therefor|
|US7777945||31 Jul 2007||17 Aug 2010||Dolby Laboratories Licensing Corporation||HDR displays having light estimating controllers|
|US7800822||31 Jul 2007||21 Sep 2010||Dolby Laboratories Licensing Corporation||HDR displays with individually-controllable color backlights|
|US7801426||24 Mar 2009||21 Sep 2010||Dolby Laboratories Licensing Corporation||High dynamic range display devices having color light sources|
|US7895088||29 Apr 2002||22 Feb 2011||Novus Partners, Llc||System permitting the display of video or still image content on selected displays of an electronic display network according to customer dictates|
|US7942531||13 Aug 2010||17 May 2011||Dolby Laboratories Licensing Corporation||Edge lit locally dimmed display|
|US7960005||16 Sep 2002||14 Jun 2011||Ochoa Optics Llc||Broadcast distribution of content for storage on hardware protected optical storage media|
|US8019688||21 Mar 2005||13 Sep 2011||Ochoa Optics Llc||Music distribution system and associated antipiracy protections|
|US8059110||8 Dec 2006||15 Nov 2011||Dolby Laboratories Licensing Corporation||Motion-blur compensation in backlit displays|
|US8090619||6 Nov 2000||3 Jan 2012||Ochoa Optics Llc||Method and system for music distribution|
|US8112311||4 Jan 2002||7 Feb 2012||Ochoa Optics Llc||Systems and methods for distribution of entertainment and advertising content|
|US8125425||31 Jul 2007||28 Feb 2012||Dolby Laboratories Licensing Corporation||HDR displays with dual modulators having different resolutions|
|US8172401||29 Apr 2011||8 May 2012||Dolby Laboratories Licensing Corporation||Edge lit locally dimmed display|
|US8199401||23 Sep 2009||12 Jun 2012||Dolby Laboratories Licensing Corporation||N-modulation displays and related methods|
|US8277056 *||5 Apr 2012||2 Oct 2012||Dolby Laboratories Licensing Corporation||Locally dimmed display|
|US8408718||26 Sep 2012||2 Apr 2013||Dolby Laboratories Licensing Corporation||Locally dimmed display|
|US8412147||31 Aug 2006||2 Apr 2013||Ochoa Optics Llc||System and method for emergency notification content delivery|
|US8419194||11 Jul 2012||16 Apr 2013||Dolby Laboratories Licensing Corporation||Locally dimmed display|
|US8446351||25 Jan 2012||21 May 2013||Dolby Laboratories Licensing Corporation||Edge lit LED based locally dimmed display|
|US8471807||1 Feb 2008||25 Jun 2013||Dolby Laboratories Licensing Corporation||Calibration of displays having spatially-variable backlight|
|US8482698||26 Nov 2012||9 Jul 2013||Dolby Laboratories Licensing Corporation||High dynamic range display using LED backlighting, stacked optical films, and LCD drive signals based on a low resolution light field simulation|
|US8656423||24 Feb 2006||18 Feb 2014||Ochoa Optics Llc||Video distribution system|
|US8684533||3 Feb 2013||1 Apr 2014||Dolby Laboratories Licensing Corporation||Projection displays|
|US8687271||7 Feb 2012||1 Apr 2014||Dolby Laboratories Licensing Corporation||N-modulation displays and related methods|
|US8719878||31 Aug 2006||6 May 2014||Ochoa Optics Llc||Video distribution system|
|US8890799||22 Feb 2013||18 Nov 2014||Dolby Laboratories Licensing Corporation||Display with red, green, and blue light sources|
|US9099046||17 Mar 2014||4 Aug 2015||Dolby Laboratories Licensing Corporation||Apparatus for providing light source modulation in dual modulator displays|
|US9147338||4 Mar 2013||29 Sep 2015||Google Inc.||System and method for emergency notification content delivery|
|US9252898||10 Oct 2008||2 Feb 2016||Zarbaņa Digital Fund Llc||Music distribution systems|
|US9270956||23 Oct 2014||23 Feb 2016||Dolby Laboratories Licensing Corporation||Image display|
|US9412337||7 Feb 2014||9 Aug 2016||Dolby Laboratories Licensing Corporation||Projection displays|
|US9478182||24 Jun 2015||25 Oct 2016||Dolby Laboratories Licensing Corporation||Locally dimmed quantum dots (nano-crystal) based display|
|US9514632||26 Oct 2015||6 Dec 2016||Google Inc.||Dangerous condition detection with user feedback|
|US9613521||22 Jul 2015||4 Apr 2017||Google Inc.||Remote sensors for detecting alert conditions and notifying a central station|
|US9659285||7 Jun 2006||23 May 2017||Zarbaņa Digital Fund Llc||Music distribution systems|
|US9711111||4 Jun 2013||18 Jul 2017||Dolby Laboratories Licensing Corporation||High dynamic range display using LED backlighting, stacked optical films, and LCD drive signals based on a low resolution light field simulation|
|US20010035853 *||19 Apr 2001||1 Nov 2001||U.S. Philips Corporation||Assembly of a display device and an illumination system|
|US20040257007 *||18 Mar 2004||23 Dec 2004||Color Kinetics, Incorporated||Geometric panel lighting apparatus and methods|
|US20050116667 *||21 Apr 2004||2 Jun 2005||Color Kinetics, Incorporated||Tile lighting methods and systems|
|US20050162737 *||13 Mar 2003||28 Jul 2005||Whitehead Lorne A.||High dynamic range display devices|
|US20070132956 *||5 Feb 2007||14 Jun 2007||The University Of British Columbia||High dynamic range display devices|
|US20070195157 *||26 Feb 2007||23 Aug 2007||Seiko Epson Corporation||Electro-optical device, electronic apparatus, and driving method|
|US20070268577 *||31 Jul 2007||22 Nov 2007||Dolby Canada Corporation||Hdr displays having location specific modulation|
|US20080018985 *||31 Jul 2007||24 Jan 2008||Dolby Canada Corporation||Hdr displays having light estimating controllers|
|US20080043303 *||31 Jul 2007||21 Feb 2008||Dolby Canada Corporation||Hdr displays with overlapping dual modulation|
|US20080174614 *||13 Feb 2008||24 Jul 2008||Dolby Laboratories Licensing Corporation||High dynamic range display devices|
|US20090180078 *||24 Mar 2009||16 Jul 2009||Lorne Whitehead||High dynamic range display devices having color light sources|
|US20090190199 *||3 Apr 2009||30 Jul 2009||Seiko Epson Corporation||Electro-optical device, electronic apparatus, and driving method|
|US20100002026 *||1 Feb 2008||7 Jan 2010||Dolby Laboratories Licensing Corporation||Calibration of displays having spatially-variable backlight|
|US20100007577 *||23 Sep 2009||14 Jan 2010||Ajit Ninan||N-modulation displays and related methods|
|US20100214282 *||17 Feb 2010||26 Aug 2010||Dolby Laboratories Licensing Corporation||Apparatus for providing light source modulation in dual modulator displays|
|US20100302480 *||13 Aug 2010||2 Dec 2010||Lorne Whitehead||Edge lit locally dimmed display|
|US20110216387 *||29 Apr 2011||8 Sep 2011||Dolby Laboratories Licensing Corporation||Edge lit locally dimmed display|
|US20120188296 *||5 Apr 2012||26 Jul 2012||Dolby Laboratories Licensing Corporation||Locally dimmed display|
|USRE41137||7 May 2007||16 Feb 2010||Charles Eric Hunter||Music distribution systems|
|EP0279032A2 *||13 Nov 1987||24 Aug 1988||International Business Machines Corporation||Passively illuminated display having colour variation|
|EP0279032A3 *||13 Nov 1987||6 Dec 1989||International Business Machines Corporation||Passively illuminated display having colour variation passively illuminated display having colour variation|
|EP0433916A1 *||14 Dec 1990||26 Jun 1991||TOSHIBA LIGHTING & TECHNOLOGY CORPORATION||Fluorescent lamp with non-deteriorative phosphor emitting blue color of light|
|WO1990014746A1 *||25 May 1990||29 Nov 1990||Ladanyi Jozsef||Discharge lamp unit with variable light intensity|
|U.S. Classification||315/324, 315/169.4, 315/363, 345/75.1, 348/799|
|International Classification||G09F13/26, G09F9/313|
|Cooperative Classification||G09F9/313, G09F13/26|
|European Classification||G09F13/26, G09F9/313|
|18 Nov 1983||AS||Assignment|
Owner name: O M E G A S A 2500 B I E N N A / SWITZERLAND
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:NOBS, ERWIN;REEL/FRAME:004196/0608
Effective date: 19831109
|1 Apr 1986||AS||Assignment|
Owner name: OMEGA ELECTRONICS S.A., RUE STAMPFLI 96, 2500 BIEN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:OMEGA SA, A SWISS CORP.;REEL/FRAME:004527/0385
Effective date: 19860324
|1 May 1989||FPAY||Fee payment|
Year of fee payment: 4
|20 Jul 1993||REMI||Maintenance fee reminder mailed|
|19 Dec 1993||LAPS||Lapse for failure to pay maintenance fees|
|1 Mar 1994||FP||Expired due to failure to pay maintenance fee|
Effective date: 19931219